This invention relates to a solar management coating system including diamond-like carbon (DLC), the system being provided on (directly or indirectly) a substrate of glass, plastic, ceramic, or the like, and a method of making the same.
Sputter coated systems for deposition on glass are known in the art for achieving solar management properties (e.g., infrared reflectance) in glass articles such as insulating glass (IG) windows, vehicle windows, architectural windows, and the like. In many such coating systems, it is desirable to provide a coating system capable of: (i) reflecting a certain amount of infrared (IR) radiation, while (ii) allowing an acceptable amount of visible light transmittance, and (iii) limiting the amount of visible light reflectance off of the coating system.
Exemplary solar management coating systems capable of reflecting infrared (IR) radiation are disclosed in U.S. Pat. Nos. 5,229,194 and 5,837,108, the disclosures of which are both hereby incorporated herein by reference.
Unfortunately, many conventional solar management coating systems are prone to scratching. Thus, they are not as abrasion resistant as would be desired.
U.S. Pat. No. 5,976,683 discloses a low-E coating system having high transmissivity in the visible spectrum and high reflectivity in the thermal radiation spectrum. A polycrystalline carbon layer crystallized with a diamond structure and doped with foreign atoms is provided and formed via CVD. Unfortunately, such polycrystalline layers are difficult and expensive to deposit on substrates and typically require very high temperatures during the deposition process (e.g., from 700 to 1,000 degrees C.). If one attempted to elevate a substrate including a low-E coating system thereon to such temperatures, many such low-E systems would be destroyed or significantly damaged. Thus, the use of a xe2x80x9cpolycrystallinexe2x80x9d diamond layer formed in such a manner over a such a system is neither practical nor desirable.
U.S. Pat. No. 5,837,108 (incorporated herein by reference) discloses a solar management coating system including, on a substrate from the substrate outwardly, a silicon nitride layer, a nickel or nickel alloy layer, and another silicon nitride layer. Unfortunately, it has been found that the solar management coating system of the ""108 patent may be susceptible to scratching in certain types of environments.
In view of the above, it will be apparent to those skilled in the art that there exists a need in the art for an improved scratch resistant and/or mechanically durable solar management coating system for use in automotive and/or architectural window applications. There also exists a need in the art for a solar management coating system that can repel water and/or dirt, and a method of making the same. There also exists a need in the art for a solar management coating system including a protective layer(s) system that can be deposited over underlying IR reflecting layer(s) via a low temperature process.
It is a purpose of different embodiments of this invention to fulfill any or all of the above described needs in the art, and/or other needs which will become apparent to the skilled artisan once given the following disclosure.
An object of this invention is to provide a solar management coating system that is scratch resistant and mechanically durable.
Another object of this invention is to provide a diamond-like carbon (DLC) inclusive protective layer(s) or coating system located over a solar management arrangement, wherein the DLC inclusive protective layer(s) or coating system can be deposited in or via a low temperature process so as to not significantly damage the existing or underlying solar management layer arrangement.
Another object of this invention is to provide a solar management coating system that is (i) scratch resistant and mechanically durable, (ii) capable of reflecting an acceptable amount of infrared (IR) radiation, (iii) capable of allowing an acceptable amount of visible light transmittance if desired, and (iv) capable of limiting the amount of visible light reflectance off of the coating system if desired.
While non-hydrophobic solar management coating systems are often desirable, there also sometimes exists a need for a solar management coating system that may be hydrophobic (i.e., can shed or repel water) if desired. Thus, another object of this invention is to provide solar management coating systems that are hydrophobic, as well as solar management coating systems that need not be hydrophobic.
Another object of this invention is to provide a scratch resistant solar management coating system including at least one diamond-like carbon (DLC) inclusive layer having at least some highly tetrahedral amorphous carbon (ta-C), wherein the ta-C includes sp3 carbonxe2x80x94carbon bonds so as to make the layer more scratch resistant and mechanically durable.
In certain embodiments, a solar management coating system may include each of a DLC inclusive layer(s) and a fluoro-alkyl silane (FAS) compound inclusive layer, wherein the DLC is provided for durability purposes and the FAS for increasing the contact angle xcex8 of the coating system.
Another object of certain embodiments of this invention is to provide a solar management coating system including sp3 carbonxe2x80x94carbon bonds and FAS, the solar management coating system having a wettability W with regard to water of less than or equal to about 23 mN/m, more preferably less than or equal to about 21 mN/m, even more preferably less than or equal to about 20 mN/m, and in most preferred embodiments less than or equal to about 19 mN/meter. This can also be explained or measured in Joules per unit area (mJ/m2)
Another object of this invention is to provide a solar management coating system having a surface energy xcex3C (on the surface of the coated article) of less than or equal to about 20.2 mN/m, more preferably less than or equal to about 19.5 mN/m, and most preferably less than or equal to about 18 mN/m.
Another object of this invention is to provide a solar management coating system having an initial (i.e. prior to being exposed to environmental tests, rubbing tests, acid tests, UV tests, or the like) water contact angle xcex8 of at least about 55 degrees, more preferably of at least about 80 degrees, still more preferably of at least about 100 degrees, even more preferably of at least about 110 degrees, and most preferably of at least about 125 degrees.
Another object of this invention is to manufacture a solar management coating system including at least one DLC inclusive layer, wherein the DLC inclusive layer is deposited in a manner such that during the DLC deposition process the underlying substrate and/or IR reflecting layer (e.g., Ag, Ni, or NiCr layer) may be kept at temperature(s) no greater than about 200xc2x0 C., preferably no greater than about 150xc2x0 C., most preferably no greater than about 80xc2x0 C.
Yet another object of this invention is to fulfill any and/or all of the aforesaid objects and/or needs.
In certain embodiments of this invention, the resulting coated article with the solar management coating system thereon may be heat treated (e.g., tempered, annealed, bent, etc.), while in other embodiments of this invention the resulting coated article need not be heat treated.
This invention will now be described with respect to certain embodiments thereof, along with reference to the accompanying illustrations.